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Drug Interactions between prazosin and Vraylar

This report displays the potential drug interactions for the following 2 drugs:

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Interactions between your drugs

Moderate

prazosin cariprazine

Applies to: prazosin and Vraylar (cariprazine)

MONITOR: Phenothiazines, tricyclic antidepressants (TCAs), and some antipsychotic (neuroleptic) agents may potentiate the blood pressure lowering capabilities of other drugs with hypotensive effects due to their peripheral alpha-1 adrenergic blocking activity. Orthostatic hypotension and syncope associated with vasodilation may occur, particularly during initial dosing and/or parenteral administration of the phenothiazine, TCA, or neuroleptic. The severity of this interaction may be affected by the agent's affinity for the alpha-1 adrenoceptor. One in vitro study demonstrated an affinity for the alpha-1 adrenoceptor for some of these medications that was similar to, or greater than, those of alpha blocker medications used to treat hypertension. Examples of drugs evaluated in this study with a high affinity included amitriptyline, clomipramine, chlorpromazine, clozapine, doxepin, flupenthixol, lurasidone, nortriptyline, perphenazine, paliperidone, quetiapine, risperidone, sertindole, and ziprasidone. On the other hand, examples of those with lower affinities included aripiprazole, lofepramine, protriptyline, sulpiride, and amisulpride.

MANAGEMENT: Close clinical monitoring for development of hypotension is recommended if phenothiazines, tricyclic antidepressants (TCAs), or certain antipsychotic (neuroleptic) agents are used in patients receiving antihypertensive medications or vasodilators. A lower starting dosage and slower titration of the phenothiazine, TCA, or neuroleptic may be appropriate, especially in the elderly. It may also be advisable to consider using a phenothiazine, TCA, or neuroleptic medication with a lower affinity for the alpha-1 adrenoceptor when possible. Patients should be counseled to avoid rising abruptly from a sitting or recumbent position and to notify their healthcare provider if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia. Patients should also avoid driving or operating hazardous machinery until they know how the medications affect them.

References

  1. Fruncillo R, Gibbons W, Vlasses P, Ferguson R (1985) "Severe hypotension associated with concurrent clonidine and antipsychotic medication." Am J Psychiatry, 142, p. 274
  2. White WB (1986) "Hypotension with postural syncope secondary to the combination of chlorpromazine and captopril." Arch Intern Med, 146, p. 1833-4
  3. (2001) "Product Information. Clozaril (clozapine)." Novartis Pharmaceuticals
  4. (2001) "Product Information. Risperdal (risperidone)." Janssen Pharmaceuticals
  5. Aronowitz JS, Chakos MH, Safferman AZ, Lieberman JA (1994) "Syncope associated with the combination of clozapine and enalapril." J Clin Psychopharmacol, 14, p. 429-30
  6. Markowitz JS, Wells BG, Carson WH (1995) "Interactions between antipsychotic and antihypertensive drugs." Ann Pharmacother, 29, p. 603-9
  7. (2001) "Product Information. Zyprexa (olanzapine)." Lilly, Eli and Company
  8. (2001) "Product Information. Seroquel (quetiapine)." Astra-Zeneca Pharmaceuticals
  9. (2001) "Product Information. Geodon (ziprasidone)." Pfizer U.S. Pharmaceuticals
  10. (2002) "Product Information. Abilify (aripiprazole)." Bristol-Myers Squibb
  11. (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc
  12. Proudman RGW, Pupo AS, Baker JG (2020) "The affinity and selectivity of alpha-adrenoceptor antagonists, antidepressants, and antipsychotics for the human alpha1A, alpha1B, and alpha1D-adrenoceptors." Pharmacol Res Perspect, 8, e00602
View all 12 references

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Drug and food interactions

Moderate

cariprazine food

Applies to: Vraylar (cariprazine)

GENERALLY AVOID: Grapefruit juice may increase the plasma concentrations of cariprazine. The proposed mechanism is inhibition of CYP450 3A4-mediated metabolism of cariprazine by certain compounds present in grapefruit. When cariprazine (0.5 mg/day) was coadministered with the potent CYP450 3A4 inhibitor, ketoconazole (400 mg/day), cariprazine peak plasma concentration (Cmax) and systemic exposure (AUC) increased by approximately 3.5- and 4-fold, respectively, while Cmax and AUC of DDCAR increased by approximately 1.5-fold each. The Cmax and AUC of another active metabolite, desmethyl cariprazine (DCAR), decreased by approximately one-third. The interaction has not been studied with grapefruit juice. In general, the effect of grapefruit juice is concentration-, dose- and preparation-dependent, and can vary widely among brands. Certain preparations of grapefruit juice (e.g., high dose, double strength) have sometimes demonstrated potent inhibition of CYP450 3A4, while other preparations (e.g., low dose, single strength) have typically demonstrated moderate inhibition. Increased exposure to cariprazine may increase the risk of adverse effects such as extrapyramidal symptoms, cognitive and motor impairment, hyperglycemia, dyslipidemia, weight gain, orthostatic hypotension, leucopenia, neutropenia, seizures, and dysphagia.

MANAGEMENT: Patients should avoid the consumption of grapefruit and grapefruit juice during treatment with cariprazine.

References

  1. Cerner Multum, Inc. "UK Summary of Product Characteristics."
  2. (2015) "Product Information. Vraylar (cariprazine)." Actavis Pharma, Inc.

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Moderate

prazosin food

Applies to: prazosin

GENERALLY AVOID: The concurrent use of ethanol and alpha-1 adrenergic blockers may cause increased hypotensive effects. Patients with aldehyde dehydrogenase deficiencies (primarily Asians) may be at a higher risk of this interaction. The mechanism has not been determined. Data exist for prazosin and other alpha adrenergic blockers are expected to interact also. In addition, any patients taking alpha adrenergic blockers may experience excessive orthostatic hypotension with ethanol ingestion, due to ethanol's unopposed vasodilatory effects in the presence of alpha adrenergic blockade.

MANAGEMENT: Patients who develop a flushing reaction after ethanol ingestion (indicates a possible aldehyde dehydrogenase deficiency) should be advised to avoid ethanol or limit their intake. All patients should be warned about the possibility of orthostatic hypotension with concurrent ethanol use.

References

  1. Kawano Y, Abe H, Kojima S, Takishita S, Omae T (2000) "Interaction of alcohol and an a1-blocker on ambulatory blood pressure in patients with essential hypertension." Am J Hypertens, 13, p. 307-12
  2. (2002) "Product Information. Xatral (alfuzosin)." Sanofi-Synthelabo Canada Inc

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Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

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Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

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